So you say that the bonus is taken into account only if it is the planet which initiates the route, therefore the starting planet.
The interface text is misleading. "MoPo I" is the destination planet. The Draths gave it to me after they surrendered to the Drengins.
I did a test with the starting planet "Torus VI", it does have the bonus, but the bonus is not taken into account either.
So yes, definitively something is wrong.

Edit: My bad, it's there "Tidally Locked" +10 %.
So yes, it seems to work only with the initiating planet.
Again, this is not well explained in the game.